[Users] Problems when branching multiple legs to asterisk

[Ardjan Zwartjes]

Hello list,

Can anybody help me with the following problem: I have a network with a
machine running OpenSER (1.1.0) and a machine running Asterisk (1.2.7).
When a call is made to a certain number on the OpenSER machine I use a
append_branch to fork the call to two phones, this works fine. The
problem arises when I want to fork the call to two extensions on the
asterisk machine. Only one of the extensions will actually start
ringing. Using ethereal I found out that OpenSER sends two invites to
the asterisk machine, asterisk returns a "100 Trying" on both invites,
but after that Asterisk seems to forget about the second call. The first
Invite is processed correctly.
	I suspect that the problem lies in the fact that asterisk
receives two calls with the same Call-ID and just drops one of them.
This behaviour is understandable since call-ids are supposed to be
unique (as far as I know). Sending two invites with the same call-id on
the otherhand also is the logical thing to do from OpenSERs point of
view, but clearly this isn't "compatible".
	So my question is: Is there some way to let OpenSER succesfully
branch a single call to two extensions on the same Asterisk? I hope
somebody knows of a way how to fix this. Thanks in advance.

Kind regards,
Ardjan Zwartjes.